By Ilana MoradyPatrick D. JoyceAdam R. Young, and Craig B. Simonsen

Seyfarth SynopsisThis week the California Department of Public Health (CDPH) issued an order revising COVID-19 definitions and procedures. Because the Cal/OSHA COVID-19 standard incorporates by reference certain CDPH definitions, the CDPH order impacts what the regulated community needs to be doing to comply with the Cal/OSHA COVID-19 standard.


On January 9, 2024, CDPH updated its COVID-19 Isolation Guidance and State Public Health Officer Order. The most impactful aspect of the update is a new definition of “infectious period.” Instead of spanning 2 days before symptoms (or positive test date in the absence of symptoms) through 10 days after symptom onset or testing positive, the new infectious period is:

For symptomatic confirmed cases, from the day of symptom onset until 24 hours have passed with no fever, without the use of fever-reducing medications, AND symptoms are mild and improving.

For asymptomatic confirmed cases, there is no infectious period for the purpose of isolation or exclusion. If symptoms develop, the criteria above will apply. 

CDPH still acknowledges that the “potential infectious period” is 2 days before symptoms (or positive test date in the absence of symptoms) through 10 days after symptom onset or testing positive, and accordingly still recommends wearing a mask through day 10. However for purposes of isolation and work exclusion, using the redefined, shorter, infectious period is recommended.

Why did CDPH make the change?

The context for the revisions is CDPH’s proclamation that “We are now at a different point in time with reduced impacts from COVID-19 compared to prior years due to broad immunity from vaccination and/or natural infection, and readily available treatments available for infected people. Our policies and priorities for intervention are now focused on protecting those most at risk for serious illness, while reducing social disruption that is disproportionate to recommendations for prevention of other endemic respiratory viral infections.” The order also explains that the revisions were made “In order for the Cal/OSHA COVID-19 Prevention Non-Emergency Standards​​​ to continue to be consistent with public health guidelines.”

What does the change mean for employers under the Cal/OSHA non-emergency COVID-19 standard?

Non-healthcare employers are still covered by the Cal/OSHA non-emergency COVID-19 standard, 8 CCR 3205, which does not expire until February 3, 2025. Under Section 3205, employers have several obligations that are significantly impacted by the shorter infectious period, the redefinition of which is incorporated by reference into Section 3205.

Shorter work exclusion: Although COVID-positive employees will still be subject to 10-day masking, employers can allow them to return to work much sooner than before, so long as symptoms are gone for 24 hours.

Close contacts: CDPH’s order specifies that the new “infectious period” definition is for the purposes of isolation and exclusion of confirmed cases. This raises the question of whether a different definition of “infectious period” should apply when making a contact-tracing determination of who might have had a close contact with the COVID-19 case. It appears possible that CDPH is still recommending a 48-hour look-back period for contact tracing based on the “potentially infectious period.” However for purposes of Cal/OSHA compliance under Section 3205, there is only one definition of “infectious period” that applies to all aspects of the regulation: the shorter infectious period that begins on the day of symptoms. It’s possible Cal/OSHA and/or CDPH may update their guidance to address this ambiguity. In any event, using a shorter infectious period for purposes of contact tracing will tend to result in a smaller pool of identified close contacts. This means that many employers will be able to winnow down the number of employees to whom they provide close contact notice and offer no-cost testing.

Outbreaks: The determination of whether an employer is in “outbreak” status under the Cal/OSHA COVID-19 standard hinges on the “exposed group” analysis. With a few exceptions, the “exposed group” is all employees who were in the same location as the COVID-19 case during the infectious period. The result of using a shorter infectious period in the analysis will likely generate smaller “exposed groups” and, accordingly, fewer “outbreaks.”

The CDPH’s order, and the resulting Cal/OSHA-compliance impacts, are welcome news for many employers. Stay tuned for the next chapter in the COVID-19 story, and in the interim, please contact the authors, your Seyfarth attorney, or any member of the Workplace Safety and Health (OSHA/MSHA) Teamfor more information on this or any related topic

Tags: CaliforniaCOVID